Relevant guidelines, in particular the EEC regulation 3820/85, regulate the conditions for the operation of utility vehicles, in particular in commercial goods traffic, with respect to the activity of the driver of the vehicle. The regulations contain specifications relating to times of availability, of driving, of rest periods and of work on, for example, the goods to be moved, especially in order to keep the stressing of the drivers of vehicles within reasonable limits and in this way to avoid traffic being put in danger through overloaded road users. In order to check for compliance with, for example, the EEC regulation, recording devices, referred to as tachographs, are provided which are compulsorily installed in the respective utility vehicles and, in particular, record the driving times and rest times of the person driving the vehicle. Since the regulatory system for working times is comparatively complicated, configuring a working day in a way which conforms with the rules, in particular when there are frequently changing types of activity, is not easy since on the part of the company, profit orientated utilization of the permissible driving times is generally desired. The tachographs which record the driving times and rest times only provide assistance to a limited degree in this context since instructions for the scheduling of a break are not provided as a standard measure and the time when the driving operation is to be interrupted cannot be output.
So that the driver of a vehicle does not have to manually calculate the rest times and driving times, which would be prone to errors, the company Capital Enterprises (2000) Ltd. has already made available a device by the name of “Driver Hour Guard” which permits time segments of specific types of activity to be input and driving times and rest times to be determined therefrom in a way which is compatible with the rules. To do this it is necessary for the driver of the vehicle to input corresponding times and types of activity into the Driver Hour Guard in parallel (in real time). In the new generation of digital tachographs the possibility of reading off information from the diagram disk is no longer provided, and data items have to be called individually from the digital tachograph and input into the evaluation device. These procedures are extremely time consuming and prone to errors.